Chromosomal aberrations in ascetic fluid of metastatic gastric cancer patients: A clustering analysis

To date, no specific pattern of chromosomal abnormalities has been established in gastric cancer (GC). Cytogenetic analysis was performed using G-banding and fluorescence in situ hybridization (FISH) in 9 ascetic fluids from GC patients, and the clustering patterns of chromosomal abnormalities were studied. Twenty-six different types of chromosomal abnormalities were identified. In contrast to structural abnormalities, the gain or loss of chromosomes was infrequent. Moreover, five main clusters of chromosomal abnormalities were identified by clustering analysis. Extensive cytogenetic complexity, specific chromosomal abnormalities and karyotype heterogeneity are the main characterizations of GC. Some of the recurrent and novel chromosomal abnormalities with distinct clustering patterns identified in this study may play important roles for GC initiation and progression and could serve as promising diagnostic and prognostic markers in GC patients.

Autologous transplant remains the preferred therapy for relapsed APL in CR2

Despite their favorable prognosis, 10-20% of acute promyelocytic leukemia (APL) patients relapse. Reinduction therapy is often followed by autologous hematopoietic cell transplantation (auto-HCT). Arsenic trioxide (ATO) has become part of standard reinduction and is often followed by auto-HCT. Data on patients in CR2 were collected from two large transplant registries (Center for International Blood and Marrow Transplant Research (CIBMTR) and European Group for Blood and Marrow Transplant (EBMT)) and two specialty referral centers. The outcome of patients in CR2 who received only ATO-based therapy as reinduction was retrospectively compared with those who got an auto-HCT, with or without ATO. Prognostic factors included age, disease risk, extramedullary disease and duration of CR1. Of 207 evaluable patients, the median age was 31.5 years, 15.3% had extramedullary disease and median WBC at diagnosis was 4.8 × 10(9)/L. Sixty-seven patients received ATO alone and 140 underwent auto-HCT. The groups were comparable for age, gender, extramedullary disease, risk group and duration of CR1. At 5 years, overall survival (OS) was 42% and 78% for the ATO-only and auto-HCT groups, respectively (P<0.001). In addition, OS was associated with longer duration of CR1 (P=0.002), but not with disease risk at diagnosis. These data suggest that auto-HCT for APL patients in CR2 results in better OS than ATO-based therapy alone.

Comprehensive mutational analysis of primary and relapse acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by differentiation block at the promyelocyte stage. Besides the presence of chromosomal rearrangement t(15;17), leading to the formation of PML-RARA (promyelocytic leukemia-retinoic acid receptor alpha) fusion, other genetic alterations have also been implicated in APL. Here, we performed comprehensive mutational analysis of primary and relapse APL to identify somatic alterations, which cooperate with PML-RARA in the pathogenesis of APL. We explored the mutational landscape using whole-exome (n=12) and subsequent targeted sequencing of 398 genes in 153 primary and 69 relapse APL. Both primary and relapse APL harbored an average of eight non-silent somatic mutations per exome. We observed recurrent alterations of FLT3, WT1, NRAS and KRAS in the newly diagnosed APL, whereas mutations in other genes commonly mutated in myeloid leukemia were rarely detected. The molecular signature of APL relapse was characterized by emergence of frequent mutations in PML and RARA genes. Our sequencing data also demonstrates incidence of loss-of-function mutations in previously unidentified genes, ARID1B and ARID1A, both of which encode for key components of the SWI/SNF complex. We show that knockdown of ARID1B in APL cell line, NB4, results in large-scale activation of gene expression and reduced in vitro differentiation potential.

Expression analysis of microRNA-125 in patients with polycythemia vera and essential thrombocythemia and correlation with JAK2 allele burden and laboratory findings

INTRODUCTION

The JAK2V617F mutation has emerged in recent years as a diagnostic as well as a treatment target in patients with polycythemia vera (PV) and essential thrombocythemia (ET). The disease phenotype is also influenced by other factors such as microRNA (miRNA) deregulation. The aim of this study was to investigate miR-125 expression level in these patients with those obtained from healthy control subjects and its correlation with JAK2 allele burden and laboratory findings.

METHODS

In total, forty patients with a clinical diagnosis of PV and ET were examined at the time of diagnosis. Ten healthy subjects were checked as controls. We performed JAK2 V617F allele burdens measurement and expression analysis of miR-125b-5p, miR-125b-3p, miR-125a-5p, and miR-125a-3p in leukocytes isolated from peripheral blood by quantitative real-time polymerase chain reaction.

RESULTS

MiR-125b-5p and miR-125a-5p were upregulated in both patients with PV (P = 0.00 and P = 0.003, respectively) and ET (P = 0.02 and P = 0.002, respectively). In PV group, a significant correlation was observed between miR-125a-5p and platelet counts (P = 0.01, r = 0.531). The correlation between miRNA and JAk2 allele burden was not significant.

CONCLUSION

In conclusion, our data indicate that other factors such as aberrant miR-125 expression may influence on the disease phenotype in patients with PV and ET.

Low frequency of c-MPL gene mutations in Iranian patients with Philadelphia-negative myeloproliferative disorders

BACKGROUND

Myeloproliferative disorders are a group of diseases characterized by increased proliferation of myeloid lineage. In addition to JAK2V617F mutation, several mutations in the c-MPL gene have been reported in patients with philadelphia-negative chronic myeloproliferative disorders that could be important in the pathogenesis of diseases. The aim of the present study was to investigate the frequency of c-MPL and JAK2V617F mutations in Iranian patients with Philadelphia-negativemyeloproliferative disorders.

MATERIAL AND METHODS

Peripheral blood samples were collected from 60 patients with Philadelphia-negative MPD) Subgroups ET and PMF) and 25 healthy subjects as control group. The mutation status of c-MPL and Jak2V617F were investigated by using Amplification-refractory mutation system (ARMS) and Allele-Specific PCR (AS-PCR), respectively. The results were confirmed by sequencing.

RESULTS

Among 60 patients, 34 (56.6%) and 1(1.7%) had Jak2V617F and c-MPL mutation, respectively. Patients with Jak2V617F mutation had higher WBC counts and hemoglobin concentration than those without the mutation (p= 0.005, p=0.003). In addition, for all healthy subjects in control group, mutations were negative.

CONCLUSIONS

The present study revealed that the c-MPL mutations unlike the Jak2V617F mutations are rare in Iranian patients with Ph-negative MPNs and the low mutation rate should be considered in the design of screening strategies of MPD patients.

Modified protocol for improvement of differentiation potential of menstrual blood-derived stem cells into adipogenic lineage

OBJECTIVES

To characterize potency of menstrual blood-derived stem cells (MenSCs) for future cell therapies, we examined differentiation potential of MenSCs into adipocytes.

MATERIALS AND METHODS

Differentiation potential of MenSCs in comparison to bone marrow stem cells (BMSCs) was assessed in conventional culture medium. Differentiation potential of MenSCs into adipocytes was improved using different combinations of growth factors and hormones.

RESULTS

First, we demonstrated that MenSCs preserve their appearance and karyotypic stability during passages. Although these cells express mesenchymal stem cells markers, they cannot simply be classified as mesenchymal stem cells due to expression of embryonic stem cells marker, OCT-4. Oil red O staining showed that differentiated MenSCs in conventional medium with/without retinoic acid (protocols 1 and 2) did not attain adipocyte characteristics, whereas differentiated BMSCs in conventional medium accumulated oil vacuoles typically. Nevertheless, real-time RT-PCR results showed that LPL gene expression was up-regulated in both protocols 1 and 2, whereas LEPR was up-regulated only in protocol 2 (fortified with retinoic acid). Surprisingly, protocol 3 (including rosiglitazone) had odd influence on mRNA expression of all genes (LEPR, LPL and PPAR-γ). Oil red O staining confirmed fat-producing ability of MenSCs under protocol 3.

CONCLUSIONS

Presented data suggest an efficient differentiation protocol for in vitro production of MenSC-derived adipocytes. These cells are suggested to be an apt alternative to BMSCs for future stem cell therapy of soft tissue injuries.

Reduced intensity conditioning is effective for hematopoietic SCT in dyskeratosis congenita-related BM failure

BM failure (BMF) is a major and frequent complication of dyskeratosis congenita (DKC). Allogeneic hematopoietic SCT (allo-HSCT) represents the only curative treatment for BMF associated with this condition. Transplant-related morbidity/mortality is common especially after myeloablative conditioning regimens. Herein, we report nine cases of patients with DKC who received an allo-SCT at five different member centers within the Eastern Mediterranean Blood and Marrow Transplantation Registry. Between October 1992 and February 2011, nine DKC patients (male, 7 and female, 2), with a median age at transplantation of 19.1 (4.9-31.1) years, underwent an allo-HSCT from HLA-matched, morphologically normal-related donors (100%). Preparative regimens varied according to different centers, but was reduced intensity conditioning (RIC) in eight patients. Graft source was unstimulated BM in five cases (56%) and G-CSF-mobilized PBSCs in four (44%) cases. The median stem cell dose was 6.79 (2.06-12.4) × 10(6) cells/kg body weight. GVHD prophylaxis consisted of CsA in all nine cases; MTX or mycophenolate mofetil were added in five (56%) and two (22%) cases, respectively. Anti-thymocyte globulin was administered at various doses and scheduled in four (44%) cases. Median time-to-neutrophil engraftment was 21 (17-27) days. In one case, late graft failure was noted at 10.4 months post allo-HSCT. Only one patient developed grade II acute GVHD (11%). Extensive chronic GVHD was reported in one case, whereas limited chronic GVHD occurred in another four cases. At a median follow-up of 61 (0.8-212) months, seven (78%) patients were still alive and transfusion independent. One patient died of metastatic gastric adenocarcinoma and graft failure was the cause of death in another patient. This study suggests that RIC preparative regimens are successful in inducing hematopoietic cell engraftment in patients with BMF from DKC. Owing to the limited sample size, the use of registry data and heterogeneity of preparative as well as GVHD prophylaxis regimens reported in this series, we are unable to recommend a particular regimen to be considered as the standard for patients with this disease.

High expression of Fas ligand on cord blood dendritic cells: a possible immunoregulatory mechanism after cord blood transplantation

BACKGROUND

Allogeneic cord blood transplantation is associated with less severe graft-versus-host disease (GVHD). Dendritic cells (DCs), as the most potent antigen-presenting cells of the immune system, play a central role in the development of GVHD. Because apoptosis induction is one of the known mechanisms that DCs use to regulate T-cell responses, we studied the immunostimulatory and apoptosis induction capacities of cord blood dendritic cells (CBDCs) and peripheral blood dendritic cells (PBDCs) to evaluate the mechanisms underlying the lower incidence of GVHD after cord blood transplantation. Presence of apoptosis-related markers Fas, Fas ligand (FasL), and CD40 and costimulatory molecules, along with the proportion of myeloid and lymphoid DCs subsets, were also measured on CBDCs and PBDCs.

METHODS

Fresh CBDCs and PBDCs were isolated from cord and peripheral mononuclear cells as lineage-negative cells by using monoclonal antibodies against CD3, CD11b, CD14, CD16, CD19, CD56, CD34, and CD66b. DCs were cocultured with allogeneic T cells, and the effect of CBDCs and PBDCs on T-cell apoptosis and proliferation were determined through flow cytometric analysis and 3H-thymidine incorporation.

RESULTS

Our findings showed that CBDCs markedly augment apoptosis of CD3+ T-cells. FasL expression on CBDCs was significantly higher than on PBDCs. However, there was no difference between Fas expression on CBDCs and PBDCs. Moreover, CBDCs were poor stimulators of allogenic T cells in mixed leukocyte reaction compared with adult peripheral blood DCs. They also displayed decreased expression of HLA-DR and CD86 molecules. The ratio of lymphoid DCs (CD11c-, CD123+) to myeloid DCs (CD11c+, CD123-) was also significantly higher in CBDCs compared with PBDCs.

CONCLUSIONS

It seems that less severe GVHD after cord blood transplantation is due not only to a higher degree of immaturity of CBDCs, but also to delivery of apoptotic signals to the host T cells that recognize allo-MHC molecules on CBDCs in the early phase of immune response.

Direct short-term cytotoxic effects of BIBR 1532 on acute promyelocytic leukemia cells through induction of p21 coupled with downregulation of c-Myc and hTERT transcription

Acute promyelocytic leukemia (APL) is characterized by specific t(15;17), distinct morphologic picture, and clinical coagulopathy that contribute to the morbidity and mortality of the disease. This study aims to investigate the effects of antitelomerase compound BIBR1532 on APL cells (NB4). BIBR 1532 exerts a direct short-term growth suppressive effect in a concentration-dependent manner probably through downregulation of c-Myc and hTERT expression. Our results also suggest that induction of p21 and subsequent disturbance of Bax/Bcl-2 balanced ratio as well as decreased telomerase activity may be rational mechanisms for the potent/direct short-term cytotoxicity of high doses of BIBR1532 against NB4 cells.

Population pharmacokinetics of oral high-dose busulfan in adult patients undergoing hematopoietic stem cell transplantation

BACKGROUND AND THE PURPOSE OF THE STUDY

Many factors have been reported that contribute to the wide intra- and inter-patient variability of Busulfan (Bu) disposition. The purpose of this study was to develop a population pharmacokinetic model and to determine the covariates affecting the pharmacokinetics (PK) of Bu in Iranian adult patients who received oral high-dose as a conditioning regimen before Hematopoietic Stem Cell Transplantation (HSCT).

METHODS

A population PK analysis was performed in 30 patients who received an oral Bu and cyclophosphamide regimen before HSCT. Bu was given orally according to the protocol of the institution. In order to prevent seizures caused by Bu, phenytoin was administered orally one hour before each dose of Bu.A total of 180 blood samples were analyzed by HPLC and PK parameters were estimated by the non-linear mixed effect model by MONOLIX 3.1 program. A one-compartment model with an additive error model was used to describe the concentration-time profile of Bu.

RESULTS

Patients' disease and weight was found to be the determinant factors for clearance (CL) and the volume of distribution (Vd) according to Monolix analysis. The covariate entered in final model followed by these equations:[Formula: see text][Formula: see text] In this limited study, the age (15-43 years) had no significant effect. For a patient weighting 60 kg, the typical CL and Vd were estimated to be 13.4 l/hr and 42.6 L, respectively. The interindividual variability of CL and Vd were 13.6 and 6.3%, respectively. There was no significant metabolic induction in these four days as is evident by comparing the trough levels of Bu. However it should be mentioned that, one tailed t-test p-values of the days of two and three, two and four and three and four were 0.083, 0.069 and 0.388, respectively.

MAJOR CONCLUSIONS

Results of this study showed that the type of disease was a determinant of CL and the weight of patient was a determinant of Vd for Bu population PK parameters. A reliable PK parameters and Css, estimated from only one plasma concentrations (5 hrs after the first dose), were validated. Since these methods require few sampling and are easy to be used, the limited sampling methods might be advantageous in the routine clinical practice.

The detection of disseminated tumor cells in bone marrow and peripheral blood of gastric cancer patients by multimarker (CEA, CK20, TFF1 and MUC2) quantitative real-time PCR

OBJECTIVE

To investigate the suitability of multimarker detection of DTCs in PB and BM of GC patients.

DESIGN AND METHOD

A qRT-PCR assay was developed to estimate the number of CEA, CK20, TFF1 and MUC2 transcripts in PB and BM samples of 35 GC patients prior to the initiation of therapy. PB samples from healthy volunteers and BM from patients with hematological malignancies were used as negative controls.

RESULTS

In PB analysis; 22.9%, 37.1%, 31.4%, and 22.9% of GC patients and in BM analysis; 20%, 28.6%, 45.7%, and 22.9% of GC patients were positive for CEA, CK20, TFF1 and MUC2 mRNAs, respectively. Samples from the control group were negative for the expression of all the markers tested in this study. A higher positive ratio was obtained with the multimarker detection in comparison to the single marker detection. There was a significant correlation between the PB and BM samples for DTC detection.

CONCLUSION

Multimarker detection assay is a reliable and powerful tool for the early detection of DTCs in GC patients.

The expression of p38, ERK1 and Bax proteins has increased during the treatment of newly diagnosed acute promyelocytic leukemia with arsenic trioxide

BACKGROUND

Promising reports exist regarding the use of arsenic trioxide (ATO) as first-line treatment in acute promyelocytic leukemia (APL). Although the in vitro effect of ATO is extensively studied, the in vivo mechanism(s) of ATO action is mostly unknown.

PATIENTS AND METHODS

Newly diagnosed APL patients were involved and received ATO (0.15 mg.kg/day) for 28 days as induction followed by consolidation therapy. Bone marrow (BM) aspirates were obtained on days 0, 14 and 28 of treatment for further molecular studies. Clinical findings and white blood cell counts were recorded as well.

RESULTS

Complete remission was observed in 17 (85%) patients with the median duration of 28 days (18-38) and cumulative dosage of median 280 mg (180-350). Hyperleukocytosis and APL differentiation syndrome (63%), gastrointestinal disorders (30%), liver enzyme elevation and night sweating (50%) were the most prevalent side-effects. The expression of Bax, ERK1 and p38 proteins and caspase-3 activity increased significantly in promyelocytes of BM aspirates at days 14 and 28 of induction therapy.

CONCLUSION(S)

These findings point toward the role of p38 and Bax in the induction of apoptosis, which was confirmed by increase in caspase-3 activity. However, the increase in ERK1 expression with regard to leukocytosis could translate to a proliferative/differentiation effect.

Cell-based regenerative therapy as an alternative to liver transplantation for end-stage liver disease: experience from iran

Several types of cells including mature hepatocytes, adult liver progenitor cells and human embryonic stem cells, fetal liver progenitor cells, bone marrow derived hematopoietic or mesenchymal stem cells, and umbilical cord blood cells-both in rodents and humans-have been reported to be capable of self-replication, giving rise to daughter hepatocytes, both in vivo and in vitro. They have been shown to be able to repopulate liver in both animal models of liver injury and in patients with liver disease and to improve liver function. Human embryonic stem cell therapy seems to be a great promise for the treatment of liver cirrhosis, but there is no human clinical application due to ethical concerns or difficulties in harvesting or safely and efficiently expanding sufficient quantities. In contrast, adult bone marrow-derived hematopoietic or mesenchymal stem cells, which can be easily and safely harvested, have been used in clinical trials to treat several chronic diseases including chronic liver disease. Cell therapy offers exciting promise for future treatment of cirrhosis and metabolic liver diseases, but significant technical hurdles remain that will only be overcome through years of intensive research. There is also serious concern about the long-term safety of stem cell therapy and the possibility of tumor development. Herein, we present our experience with cell therapy in treatment of chronic liver disease in Iran.

Phase II trial of old age acute myeloid leukemia treatment by arsenic trioxide and low-dose subcutaneous cytosin arabinoside

7075

Background: AML is a disease of old age, but unfortunately due to several factors standard treatment can not be delivered to these patients. Here we tried to achieve to bet possible response to these patients. Methods: Eleven old age patients selected for this trial. Patients couldn't tolerate standard treatment of AML due to old age or comorbid disorders. Treatment consist of best supportive care plus administration of low dose ARA-C (20mg/day as SQ) for 10 days each months and arsenic trioxide 10 mg/day as 2 hour iv infusion each month. Patients followed by CBC and BMA/B when peripheral blood normalized or every other month. Results: This cohort consist of 8 men and 3 women. Median age was 75 y/o (55–80). Median WBC count Hb level and platelet count at presentation were 42,860μl, 8.3g/dl and 30,500/μl, respectively. Complete remission observed in 6 and partial remission in one patient (RR = 63.6%), but remission was short live, after 6 months one patient was in CR and one in PR. After 12 months, only one patient was in PR. Median survival was 6 months and 6 patients survive more than 6 months. Two patients are alive after 12 months. Conclusions: Although prognosis of old age AML remain poor, but with this type of treatment RR is acceptable. In this very high-risk group of very old AML, combination of ATO and ARA-C possibly could improve survival.

No significant financial relationships to disclose.

Outpatient stem cell transplantation for multiple myeloma

e19553

Background: The aim of this study was to explore the feasibility and safety of performing aoutologous stem cell transplantation (ASCT) on an outpatient basis. Methods: 142 patients with multiple myeloma (MM) in complete remission (CR) or partial remission (PR) received ASCT on an outpatient or inpatient basis. In the inpatient group 77 patients and in outpatient group 65 patients received 200 or 140 mg/m2 melphalan as conditioning regimen respectively. In outpatient group all the patients were programmed to go home the day after ASCT and to be re-hospitalized in the case of febrile neutropenia or other sever toxicities. We used caregiver, general physician, staff nurse as an outpatient and visit team and also unequipped routine house of the patients during neutropenia. Results: Median age was 50.2 years (ranged 27–68) with 70% male. Median hospital stay were 25 days in inpatient and. 4.8 days in outpatient respectively (p<0.01). There were not significant differences between these groups in aphresis days, granulocyte colony stimulating factor requirement for mobilization and mononuclear cell, There were also significant reduction (p<0.001) in parenteral antibiotic, blood product requirement and need for total parenteral nutrition. The most frequent causes of re-admission (outpatient group) were febrile neutropenia and sever mucositis need TPN. 2 years overall survival rate was 98.2% (SE=2%) in inpatient groups and 86.6% (SE=5.7) in outpatient groups.We did not have any death in first month after transplantatio in outpatient group. Conclusions: We describe an outpatient program based on management of the patient in his/her house during aplastic phase. Our results clearly indicate that such a procedure is feasible and safe in a patient population with a caregiver.

No significant financial relationships to disclose.

Outpatient versus inpatient autologous stem cell transplantation for malignant hematologic disorders

7042

Background: High-dose chemotherapy with autologous stem cell support is utilized for the treatment of a variety of malignancies including Hodgkin/non-Hodgkins lymphoma and acute leukemias. The aim of this study was to compare the time of engraftment and mortality rate and cost of neutropenic treatment in outpatient versus inpatient autologous stem cell transplantation (SCT). Methods: 9 outpatients (5 HL, 2 NHL, and 2 AML) were compared with 32 inpatients (15 HL, 8 NHL, and 9 AML; for whom the outpatient facilities were not ready) from May 2008 to December 2008. All patients were below 45 yrs; median age for outpatients and inpatients were 26 and 30 years respectively. Also all the patients were in complete remission and without significant organ failure. They received conditioning regimen (CEAM for NHL and HL, busulfan and etoposide for AML) and stem cell infusion in hospital. The day after SCT, outpatient group were discharged and followed by outpatient SCT team, and to be re-hospitalized in case of febrile neutropenia, after sepsis workup and performing chest x-ray, they were received the first dose of antibiotic in hospital and treatment continued in home. Results: For outpatients and inpatients, median time to WBC engraftment was 11 and 12 days (p = 0.03), time to PLT engraftment was 15 and 25 days (p = 0.20), number of transfused single donor PLT was 3 and 4.5 units (p = 0.21), duration of neutropenic fever was 6 and 9 days (p = 0.001), duration of hospitalization (after SCT) 0 and 16 (p < 0.001), respectively. All outpatients are alive and 3 patients from other group died between days +35 and +100 after SCT due to transplantation complications. For inpatient group the cost of drugs, just for neutropenic fever antibiotic therapy was six times than outpatient group. Conclusions: Results show that out-patient autologous SCT in malignant hematologic disorders is feasible and comparable with inpatient protocol. We are waiting for more patients and longer follow-up for future conclusions.

No significant financial relationships to disclose.

First-line treatment of acute promyelocytic leukemia with arsenic trioxide without ATRA and chemotherapy

7073

Background: Standard treatment of APL is ATRA plus chemotherapy but Arsenic Trioxide (ATO) is most potent single agent against APL cells. Role of ATO in first line therapy of APL needs to clarify. Methods: Between may 2000 and September 2006,we treated 141 new cases of APL(Median age 28±12.8 y/o min=11,max=71) by 2 hours iv infusion of 0.15mg/kg ATO until complete remission. Trial approved by IRB and consent form obtained. Diagnosis was by clinical and morphologic characteristics and confirmed by cytogenetic and RT-PCR for detection of t(15,17) and presence of PML-RARa. After complete remission patients received consolidation by 28 days infusion of ATO for one or four courses.(one consolidation one month after CR and for some patients second, third and forth consolidations one month after first one and two another , one year and two year after CR) Results: : complete remission observed in 121 cases(85.8%) and early mortality rate was14.9%(most common cause of early mortality was APL syndrome,61.9%).Median follow up was 28 months. For patients who achieve to complete remission,one, two and three year disease free survival were 95.6%± 2%, 76.9±4% and 57± 6%,respectively. Many relapsed patients salvaged again with ATO alone so, two and three years overall survival for this cohort was 95.6%±2% and 83.7%±4%. Increasing number of consolidation from one to four couldn’t increase DFS or OS in one and two years after CR. Conclusions: ATO is effective in treatment of new cases of APL. Introduction of ATO in first line treatment of APL(with or without ATRA plus chemotherapy) needs a multi center randomized clinical trial.

No significant financial relationships to disclose.

Risk factors for early mortality, relapse and overall survival in new cases of APL treated by arsenic trioxide

7069

Background: There are several known risk factors for APL treatment by ATRA and chemotherapy, but risk factors for new cases of APL treated by Arsenic Trioxide are unknown. Methods: Between May 2000 and September 2006, we treated 141 new cases of APL (Median age 28±12.8 y/o min=11, max=71) by 2 hours iv infusion of 0.15mg/kg ATO until complete remission. Trial approved by IRB and consent form obtained. Diagnosis was by clinical and morphologic characteristics and confirmed by cytogenetic and RT-PCR for detection of t(15,17) and presence of PML-RARa. After complete remission patients received consolidation by 28 days infusion of ATO for one or four courses. Known risk factors for APL treatment outcome (including PML-RARa isoforms, presence of MRD during follow up and WBC count at presentation analyzed for early mortality, relapse rate, DFS and OS. Results: Complete remission observed in 121 cases (85.8%) and early mortality rate was 14.9%. short isoform of detected in 36% of patients and 18% presented by WBC more than 10,000/μl. For early mortality, APL differentiation syndrome during treatment and WBC count more than 10,000/μl were risk factors. (P<0.001 and p=0.011 respectively) For DFS only predicting factor for relapse was detection of MRD (by nested PCR or by real time PCR) during follow up (P=0.05). For prediction of OS, again only risk factor was detection of MRD(P<0.0001). Conclusions: Although WBC count before treatment and APL differentiation syndrome during treatment are risk factor for relapse, short isoform of APL is not a risk factor. After achieving to CR only risk factor is detection of MRD.

No significant financial relationships to disclose.

Fludarabine and busulfan as a myeloablative conditioning regimen for allogeneic stem cell transplantation in high- and standard-risk leukemic patients

Busulfan and cyclophosphamide (BuCy) are currently the most widely used myeloablative regimen to treat malignancies with allogeneic stem cell transplantation. Fludarabine has considerable efficacy in both immunosuppression and tumor cells killing with a minimal extramedullary toxicity. We evaluated the efficacy of 40 mg/m(2) fludarabine i.v. for 5 days and busulfan 4 mg/kg/day p.o. for 4 days as myeloablative conditioning regimen in 70 patients (median age 24 years) with acute leukemia or chronic phase of myelogenous leukemia. They all had human leukocyte antigen-matched sibling donors. The patients received 10 mug/kg granulocyte colony stimulating factor (GCSF), 24 h after stem cell infusion until engraftment occurred. Graft-versus-host disease (GVHD) prophylaxis included 3 mg/kg cyclosporine-A i.v. from day -2 to +6 followed by 12 mg/kg p.o. until day +60. The median time of neutrophil recovery (>0.5 x 109/l) and platelet recovery (>20 x 109/l) were 10 and 12 days, respectively. Mucositis (93%) and hepatic toxicity (16%) resolved with conservative therapy. The incidence of acute GVHD grade I-II and III-IV were 38.6 and 15.7% respectively. Overall survival and disease-free survival were 71 and 64% respectively with 17 months median follow-up for surviving patients. We conclude that FluBu may be used as a substitute for BuCy with almost the same efficacy and with a lower transplant adverse effect but to increase anti-leukemic effects, especially in acute lymphoblastic leukemia patients, it needs some modifications.